Spindle drive track assembly for cotton pickers



I Oct. 29, 1963 R. c. FERGASON SPINDLE DRIVE TRACK ASSEMBLY FOR COTTON PICKERS 2 Sheets-Sheet 1 Filed April 10, 1961 Oct. 29, 11963 c. FERGASON SPINDLE DRIVE TRACK ASSEMBLY FOR COTTON PICKERS 2 Sheets-Sheet Filed April 10, 1961 United States Patent 3,108,419 SPINDLE DRIVE TRACK ASSEMBLY FGR COTTON PICKERS Rector C. Fergason, La Porte, Ind, assignor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis. Filed Apr. 10, 1961, Ser. No. 101,863 5 Claims. (CI. 56-42) The invention relates to cotton picking machines and it is concerned more particularly with a mechanism for rotating lint gathering spindles during the picking operation.

In a well known type of cotton picking machine which is disclosed, for instance, in U.S. Patent 2,671,298, issued March 9, 1954 to R. C. Fergason, each picking spindle has a drive roller near one end, and rotation of the spindles during the picking operation is obtained by moving the rollers along stationary tracks of resilient material such as rubber. Frictional engagement of the rollers with the tracks causes the spindles to rotate as the rollers are moved from one end of the track toward the other.

In machines of this type, it is common practice to combine the drive track for an upper row of picking spindles and the drive track for a lower row of picking spindles into a unitary assembly which can be conveniently installed on and removed from the machine. Such an assembly conventionally includes, in addition to the rubber tracks, a pair of backing plates for the tracks, a series of springs for spreading the backing plates laterally apart and thereby urging the rubber tracks into frictional engagement with the upper and lower spindle rollers, and various parts for holding the assembly together and mounting it on the machine.

The springs for spreading the track backing plates apart have heretofore been made in various shapes. According to one suggestion the springs were made of pieces of sheet steel doubled back so as to provide two spring arms which could be deflected toward each other between a pair of opposite track backing plates. By spreading the backing plates laterally apart the springs were effective to force the associated rubber tracks into frictional engagement with overlying and underlying spindle rollers. The use of sheet steel for the springs was not entirely satisfactory mainly because ordinary manufacturing methods resulted in springs of widely varying deflection characteristics.

In order to provide more uniform deflection characteristics of the springs, it was suggested to make them of steel wire and in the form of the well known mousetrap springs. However, the mousetrap springs also had shortcomings, particularly in the matter of undue stress concentrations near the coils and resulting breakage.

Both the sheet steel springs as well as the mousetrap springs require retaining and mounting structures which are relatively expensive, difiicult to make, and cumbersome to assemble and install.

In the mentioned spindle drive track assemblies in which the spring arms are deflected toward each other between the track backing plates the free ends of the spring arms bear against the track backing plates only at one point or at best along a short edge line which extends generally in the longitudinal direction of the track. Such localized contact between the spring arms and the track backing plates permits the plates and associated tracks to rock laterally about their points or lines of contact with the springs, and this instability of the tracks is undesirable from an engineering standpoint as well as from a performance standpoint.

It is an object of the present invention to provide an improved spindle drive track assembly for cotton pickers which avoids the hereinbefore outlined difficulties and shortcomings of the prior art in a practical and entirely satisfactory manner.

3,198,419 Patented Got. 29, 1963 Another object of the invention is to provide an improved device for spreading opposite spindle drive tracks of a cotton picker apart, the improved device comprising a support and a series of springs which can be manufactured and assembled most economically.

A further object of the invention is to provide an improved spindle drive track assembly of the mentioned character which is simpler in construction, more efficient in operation, less space consuming and cheaper to manufacture than the heretofore known assemblies wherein sheet steel or wire springs have been used for spreading opposite spindle drive tracks apart.

A still further object of the invention is to provide an improved spindle drive track assembly of the hereinabove outlined character which lends itself for use in machines having a conventional conveying mechanism for moving the picking spindles horizontally in an endless oblong path, the improved spindle drive track assembly being such as to require no change in the design, construction or operation of the conventional spindle conveying mechanism, or in the design, construction, or operation of the picking spindles.

The foregoing and other objects and advantages are attained by the present invention, various novel features of which will be apparent from the description herein of an embodiment of the invention, and will be set forth in the appended claims.

Referring to the accompanying drawings:

FIG. 1 is a fragmentary elevational view of a cotton picking mechanism, parts being broken away and shown in section;

FIG. 2 is a fragmentary enlarged top view of a spindle drive track assembly as installed in the mechanism shown in FIG. 1;

FIG. 3 is a fragmentary top view of a track spreading device forming part of the assembly shown in FIG. 2;

FIG. 4 is a section on line IV-IV of FIG. 2 showing the spindle drive track assembly as installed in the mechanism shown in FIG. 1;

FIG. 5 is a sectional view showing the spindle drive track assembly of FIG. 4 in noninstalled condition;

FIG. 6 is a section on line VI--VI of FIG. 2;

FIG. 7 is an enlarged section on line VII-VII of FIG. 3;

FIG. 8 is a section similar to FIG. 7, but showing a modified spring design; and

FIG. 9 is an enlarged section on line IXIX of FIG. 2;

The picking mechanism shown in FIG. 1 is similar in general construction and mode of operation to the one shown in the hereinbefore mentioned US. Patent 2,671,- 298. In accordance with established practice, a frame structure 1 provides a support for a series of stationary vertically spaced stalk guide channels 2 and a vertical series of vertically spaced stalk crowder beams in the form of angle irons 3 opposite to the stalk guide channels 2. The vertical space between the channels 2 and angles 3 defines a picking tunnel into which the cotton plants are crowded during operation of the machine. Cotton lint is picked from the cotton plants within the tunnel by rotary picking spindles which are mounted on vertical slats and moved horizontally through the picking tunnel by an endless conveying mechanism including chains 4 and 5.

One of the spindle carrying slats is designated in FIG. 1 by the reference character 6, and alternate picking spindles which are rotatably mounted on the slat are designated by the reference characters 7 and 7, respectively. Twin bearings 8 are spaced from each other longitudinally of the slat '6, and each bearing 8 mounts the inner end of a spindle 7 in its upper part, and the inner end of a spindle 7' in its lower part. Drive rollers 9 and 9 are secured to the spindles 7 and 7, respectively, adjacent the bearings 8, and the spindles are additionally supported on bearings 10 spaced axially outward from the twin bearings 8.

Operatively interposed between each pair of upper and lower spindle rollers 9 and 9' are spindle drive track assemblies generally designated in FIG. 1 by the reference character 11. Each spindle drive track assembly 11 comprises a pair of vertically opposed rubber tracks 12 and 13 in frictional engagement with upper and lower spindle drive rollers 9, 9', respectively. As shown in FIG. 2, the spindle drive track assembly 11 is arcuately elongated and the rubber track 12 presents a top surface of substantial arcuate length along which rollers 9' are moved in endless succession during operation of the machine. The radial width of the track 12 is slightly greater than the axial length of the roller 9', as shown in FIG. 4. The same relation which exists between the upper track 12 and the adjacent lower spindle roller 9' exists between the lower track 13 and the adjacent upper spindle rollers 9.

Referring to FIGS. 4 and 5, it will be seen that the rubber tracks 12 and 13 are supported by thin, flexible, backing plates 17 and 18, respectively. As shown in FIG. 2, the backing plate 17 is arcuately elongated and extends the full arcuate length of the assembly 11. The radial width of the backing plate 17 is substantially greater than the radial width of the track 12, as shown in FIG. 4. The same explanations apply analogously to the backing plate 18 for the lower track 13.

A spreading device for the backing plates 17 and 18 and associated rubber tracks is shown separately in FIG. 3 and comprises an elongated arcuate plate member 19 and a series of coiled axially compressible wire springs 21 which are mounted on the plate member 19 in upstanding relation thereto. The plate member 19 has a right angle bend along one edge, as shown in FIGS. 4 and 5, and a wear strip 22 is secured, as by welding, to the radially outer, bent over edge portion of the plate 19. The springs 21 are of hourglass shape and are threaded into holes 23 of the plate member 19 as best shown in FIGS. 7 and 8. The mounting hole 23 for the hourglass spring shown in FIG. 7 has a diameter just large enough to accommodate the center portion of the spring. That is, the diametrically smallest portion of the spring is closely surrounded by the circular wall which defines the hole 23, and the springs of the entire series are, therefore, accurately held at fixed distances from each other by the plate 19.

The springs 21 are wound into their final hourglass shape before they are installed on the plate member 19'. In order to mount the springs in their respective holes 23 it is merely necessary to insert one of the free ends of the spring in the hole and then turn the spring on its axis so that its turns will advance into the hole until the center portion of the spring settles in the hole. In other words, the springs may be threaded like screws into the holes 23 and require no separate fastening means for holding them in installed positions on the plate member 19.

As shown in FIGS. 2. and 4, the spindle drive track assembly r11 includes a channel member 24 which is curved generally the same as the arcuate radially inner edge of the plate member 19 and which extends lengthwise of the latter from end to end and somewhat beyond the forward end of the plate member 19 at the bottom of FIG. 2. The open side of the channel member 24 faces radially outward, and its web extends at right angles to the plane of the plate member 19 in close proximity to the radially inner edge of the latter.

Projecting radially inward from the plate member 19, as shown in FIG. 3, are a mounting clip 14 at the forward end of the plate member, a retaining clip 26 at an intermediate portion of the plate member 19, and another retaining clip 27 at the rear end of the plate member 19. As shown in FIG. 6, the clip 14 comprises upper and lower strips which are secured to the upper and lower faces, respectively, of the plate member 19, preferably by spot welding, and the radially inner end of the clip 14 projects through a hole in the web of channel member 2 4- and has a hole 28 for reception of a vertical locking pin 16 as shown in FIG. 1. The retaining clip 26 as shown in FIG. 4 is a sheet metal strap doubled back over the upper and lower sides of the plate member 19 and secured thereto by a tubular rivet 29. The radially inner end of the clip 26 projects through a hole in the web of the channel member 24 and has a hole 31 for the reception of a short locking pin 32 (FIGS. 4 and 5). The retaining clip 27 is a duplicate of the retaining clip 26 and is secured to the plate member 19 by another tubular rivet 34. The end of the clip 27 which projects through the web of the channel member 24 has a hole 33 for the reception of a short locking pin 36- corresponding to the locking pin 32.

In the assembled condition of the entire spindle drive track assembly '11 the radially inner arcuate edge of the backing plate 17 extends under the upper flange of the channel member 24 and the forward end of the backing plate 17 next to the mounting clip 14 is secured to the latter by means of two rivets 37 and 38 as best shown in FIGS. 2 and 6. The backing plate 17 has an intermediate retaining clip 39 (FIG. 2) similar to the retaining clip 26 of the plate member 19 and directly above the latter. A rearward retaining clip 41 corresponding to the intermediate retaining clip 39 is secured to the backing plate 17 in overlying relation to the retaining clip 27 of the plate member 19. The retaining clips 39 and 41 of the backing plate 17 project through the same openings of the web of the channel member 24- as the clips 26 and 27 of the plate member 19, and the short locking pins 32 and 36 which extend through the holes 31 and 33' of the clips 26 and 27 also extend through corresponding holes of the clips 39' and 41.

The foregoing explanations regarding the upper backing plate 17 analogously apply to the lower backing plate 18. That is, the forward end of the lower backing plate I18 next to the mounting clip 14 is secured to the latter by the rivets 37 and 38, and the short locking pins 32 and 36 which extend through the retaining clips 39 and 41 of the upper backing plate also extend through corresponding retaining clips of the lower backing plate. Cotter pins 40 and 40' extend through opposite ends of the locking pin 32 in order to keep it from falling out, and the locking pin 36 is similarly retained in position on the assembly.

When the spindle drive track assembly 11 has been assembled and before it is installed in the machine, its backing plates 17 and 18 are relatively positioned as illustrated by FIG. 5. That is, the backing plates 17 and 18 and the associated rubber tracks 12 and 13 are spread apart by the hourglass springs 21 into diverging positions, but are prevented from coming apart by reason of the forward rivets 37 and 38, and by the retaining action of the pins 32 and 36 and also by the restraining action of the upper and lower flanges of the channel member 24.

As shown in FIG. 1, the channel member 24 of each spindle drive track assembly 11 is straddled by the legs of a channel member 42 which forms part of the frame structure 1. Each of the channels 42 is arcuately elongated like the channel member 24 of its associated spindle drive track assembly, and in order to install the spindle drive track assembly on the machine each spindle drive track assembly is pulled in the direction of its length into position between a horizontal row of lower spindle drive rollers 9 and a horizontal row of upper spindle drive rollers 9. While the spindle drive track assembly is thus drawn into position, the upper and lower backing plates 17 and 18 are forced toward each other due to con- 5 tact of the upper and lower drive tracks with the adjacent upper and lower spindle rollers. When the spindle drive track assemblies, as shown in FIG. 2, are installed, their backing plates 17 and 18 extend parallel to the horizontal portions of their associated plate members 19, as shown in FIG. 4.

The channels 42 have aligned holes in their upper and lower flanges with which the holes 28 of the mounting clips 14 register when the spindle drive track assemblies 11 are in place on the machine. Insertion of the locking pin 16 through the holes in the channels 42 and the registering holes 28 of the mounting clips 14 secures the spindle drive track assemblies against lengthwise displacement relative to the frame structure 1, but does not prevent the plate members 19 from adjusting themselves vertically as needed.

The hourglass springs 21 have axially successive turns in radially spaced relation to each other. Consequently, each spring may be radially compressed into a nully collapsed condition, as shown in FIG. 4, in which the turns above the constricted midportion of the spring are deflected into a plane horizontal spiral above the plate member 19, and in which the turns below the constricted midportion of the spring are similarly deflected into a plane horizontal spiral below the plate member 19.

It will be noted that the underside of the backing plate 17 is engaged by a spirally coiled portion of each hourglass spring and that the upper side of the lower backing plate 18 is similarly engaged by a spirally coiled portion of each hourglass spring, when the assembly is in a state of vertical compression between horizontal upper and lower rows of spindle rollers 9, '9. The rubber tracks are bonded to the upper and lower faces of the backing plates 17 and 18, respectively, and their thicknesses, when new, are such that the upper and lower par-ts of the hourglass springs will be deflected int-o substantially plane horizontal spirals above and below the plate member 19, as shown in FIG. 4, when the spindle drive track assemblies are in place on the machine. As the rubber tracks wear in operation of the machine, the upper and lower portions of the hourglass springs will gradually expand axially outward from their horizontally plane spiraled conditions, and the springs will thus be effective to maintain adequate pressure of the tracks against the rollers during the picking operation. The spiraled contact areas between the springs 21 and the backing plates 17, 1'8 stabilize the tracks 12 and 13 against lateral tilting.

The hourglass spring 21 shown in FIG. 7 is wound of steel wire of uniform circular cross section and has a radially constricted midportion comprising two turns 20 and 25 of approximately the same diameter and in axially abutting engagement with each other. The diameter of the hole 23 in plate member 19 is slightly larger than the outside diameter of the turns 20 and 25, so that it will accommodate the turns 20 and 25 with very little radial play. The portion of (the spring 21 which extends spirally upward from the turn 20' presents axially successive turns of gradually increasing radius, but the pitch between these turns is uniform and indicated by the double headed arrow 43. The same explanations apply to the portion of the spring 21 which extends spirally downward from the turn 25. When the spring 21 is compressed to the contracted condition illustrated by FIG. 4, the deflection stresses in the spring wire will be greatest near the radially constricted midportion of the spring and will gradually decrease toward the radially enlarged opposite ends 46 and 47 of the spring, according to well known principles. The combined vertical height of the two center turns 20, 25 is somewhat greater than the thickness of the plate member 19, and in the axially compressed condition of the spring 21 as shown in FIG. 4, several turns of the spring above the plate 19 bear against the underside of the backing plate 17, and several turns of the spring below the plate '19'bear against the upper side of the backing plate '18.

In order to obtain a more uniformly stressed condition of the spring when it is compressed axially, the pitch between successive turns of the spring may be graduated so that it will increase axially of the spring in opposite directions from the radially constricted midportion. An hourglass spring 48 in which the pitch gradually increases from the center toward theaxially opposite ends is illustrated in FIG. 8. The radially constricted midportion of the spring 48 in FIG. 8 comprises two closely adjacent turns 49, 51 of approximately the same outside diameter, and these two turns are accommodated snugly by the hole 23 of the plate member 19. The portion of the spring 48 which extends spirally upward from the turn 49 presents axially successive turns which are not only of gradually increasing radius, but also of gradually increasing pitch. It will be seen that the pitch 52 of a turn adjacent to the constricted midportion of the spring is substantially shorter than the pitch 53 of a turn near the upper end of the spring. The same explanations apply to the portion of the spring which extends spirally downward from the turn 51. The gradual pitch increase of the successive turns of the upper and lower parts of the spring 48 may readily be so determined that the internal stresses of the spring wire will be substantially uniform in the deflected spring portions when the spring is compressed to an axially contracted condition in which the upper part assumes the shape of a plane horizontal spiral above the plate member 19, and in which the lower part of the spring assumes the shape of a plane horizontal spiral below the plate member 19. The spring shown in FIG. 8 may be used in lieu of the uniformly pitched spring shown in FIG. 7 if it is desired to obtain a stronger separating force between the backing plates 17 and 18 than is obtainable with the spring design shown in FIG. 7.

It will be noted that the herein disclosed spindle drive track assembly is relatively simple and economical to manufacture and that it lends itself for use in machines having a conventional conveying mechanism for the picking spindles. Use of the improved spindle drive track mechanism neither requires a change in the construction of the conventional spindle conveying mechanism nor a change in the design of conventional picking spindles such as the picking spindles 7 and 7' with their associated drive rollers 9 and 9 shown in FIG. 1. The spreading device for the tracks 12 and 13 comprises, generally, a plate member as represented by the plate member 19, and a series of coiled axially compressible wire springs each having successive turns of continually increasing diameter, as represented by either half of the hourglass spring 21 in FIG. 7, or by either half of the hourglass spring 48 in FIG. 8, the springs being mounted on their radially smallest portions, respectively, on the plate member 19 in upstanding relation thereto.

It is not intended to limit the invention to the exact construction herein shown and described for purposes of illustration, as various modifications within the scope of the appended claims may occur to persons skilled in the art.

What is claimed is:

1. A spindle drive track assembly for cotton pickers comprising elongated upper, lower and intermediate plate members in superimposed relation to each other, said intermediate plate member having a longitudinal series of holes therein; a pair of upper and lower spindle drive tracks secured, respectively, to the upper and lower sides, respectively, of said upper and lower plate members, a series of coiled, axially compressible wire springs extending through said series of holes, respectively, in said intermediate plate member and bearing against the lower and upper sides, respectively, of said upper and lower plate members opposite to said upper and lower drive tracks, and means coacting with said upper and lower plate members for limiting vertical separating movement thereof.

2. A spindle drive track assembly as set forth in claim 1, wherein said intermediate plate member has said series of holes in the portion thereof between said spindle drive tracks, and wherein said wire springs are hourglass shaped and threaded, respectively, into said holes so that upper and lower coiled portions of said springs are positioned, respectively, above and below said intermediate plate member.

3. A spindle drive track assembly for cotton pickers comprising elongated upper, lower and intermediate plate members in superimposed relation to each other, said intermediate plate member having a longitudinal series of holes therein; a pair of upper and lower spindle drive tracks secured, respectively, to the upper and lower sides, respectively, of said upper and lower plate members, a series of coiled, axially compressible wire springs extending through said series of holes, respectively, in said intermediate plate member and bearing against the lower and upper sides, respectively, of said upper and lower plate members opposite to said upper and lower drive tracks, and a channel member extending lengthwise of said upper, lower and intermediate plate members and having upper and lower flange portions in overlying and underlying relation, respectively, to said upper and lower plate members.

4. A spindle drive track assembly for cotton pickers comprising elongated upper, lower and intermediate plate members in superimposed relation to each other, said intermediate plate member having a longitudinal series of holes therein; a pair of upper and lower spindle drive tracks secured, respectively, to the upper and lower sides, respectively, of said upper and lower plate members, a series of coiled, axially compressible wire springs extending through said series of holes, respectively, in said intermediate plate member and bearing against the lower and upper sides, respectively, of said upper and lower plate members opposite to said upper and lower drive tracks, a channel member having an apertured web portion extending transversely of said intermediate plate member along a longitudinal edge portion of the latter remote from said springs, and at least one retaining clip secured to said intermediate plate member and extending therefrom through an aperture of said web portion, said channel member having upper and lower flange portions in overlying and underlying relation, respectively, to said upper and lower plate members.

5. A spindle drive track assembly as set forth in claim 4 and further comprising a wear strip secured to said intermediate plate member along a longitudinal edge portion thereof adjacent to said springs.

References Cited in the file of this patent UNITED STATES PATENTS 2,665,536 Rust Jan. 12, 1954 2,783,602 Fergason Mar. 5, 1957 2,968,904 Fergason Jan. 24, 1961 

1. A SPINDLE DRIVE TRACK ASSEMBLY FOR COTTON PICKERS COMPRISING ELONGATED UPPER, LOWER AND INTERMEDIATE PLATE MEMBERS IN SUPERIMPOSED RELATION TO EACH OTHER, SAID INTERMEDIATE PLATE MEMBER HAVING A LONGITUDINAL SERIES OF HOLES THEREIN; A PAIR OF UPPER AND LOWER SPINDLE DRIVE TRACKS SECURED, RESPECTIVELY, TO THE UPPER AND LOWER SIDES, RESPECTIVELY, OF SAID UPPER AND LOWER PLATE MEMBERS, A SERIES OF COILED, AXIALLY COMPRESSIBLE WIRE SPRINGS EXTENDING THROUGH SAID SERIES OF HOLES, RESPECTIVELY, IN SAID INTERMEDIATE PLATE MEMBER AND BEARING AGAINST THE LOWER AND UPPER SIDES, RESPECTIVELY, OF SAID UPPER AND LOWER 